Throttle valve for fluid actuated rotary tools



Oct. 2, 1951 P. E. SCHMID THROTTLE VALVE FOR FLUID ACTUATED ROTARY TOOLS 2 Sheets-Sheet 1 Filed June 19, 1948 Paul E. \Scbm/a INVENTOR.

Oct. 2, 1951 SCHMID 2,570,009

THROTTLE VALVE FOR FLUID ACTUATED ROTARY TOOLS Filed June 19, 1948 2 Sheets-Sheet 2 A TTOR/VEY Patented Oct. 2 1951 UNITED STATES PATENT OFFICE 2,570,009 THROTTLE VAIIYE FOR FLUID Ac'rUArEi) ROTARY TOOLS Paul E. sehmia; Houston, Tex., assignor to Reed Roller Bit Company, Houston, Tex., a corporation of Texas Application Jane 19, 1948-,- Serial No. 34,011

6 Claims.

This invention pertains broadly to fluid actuated portable tools, but more specifically to afl'uid actuated tool of the rotary type.

One object of this invention is to produce a fluid actuated portable tool with an improved throttle valve construction which is readily manipulable by the operator when normally holding the tool to the work.

Another object of this invention is 'to provide such a tool with a throttle valve assembly constructed and arranged whereby the throttle valve operatinghandle forms a normal continuation of the tool housing and is so located and shaped as to form a handle'for the tool adapted to be grasped by one hand of the operator when supporting the tool to the work.

Another object of this invention is to produce a tool of this type which has a simple, substantially cylindrical appearance throughout its length and is therefore deprived of protuberances in the form of throttle talve operating handles such as heretofore found in tools of this type,

which protuberances have been found to be cumbersome and uncomfortable to the handsof the operator. I

Another object of this invention is to provide such a tool with a simple and efficient throttle valve without resorting to the use of packings,

taper seats or spring pressed balls usually found in throttle valves of fiuid actuated tools.

Another object of this invention is to provide such a tool with a throttle valve operating handle which is also used as a deflector for motive fluid exhausting from the tool.

A still fiirther object of this invention is to produce a fluid actuated tool having a rotary vane type motor with simple and efficient means for relieving pressure fluid which might accidentally have seeped below the vanes and would cause the vanes to exert detrimental pressure against the inner wall of the stator as well as retard their inward movement and reduce the efilciency of the motor.

Other objects and advantages more or less ancillary to the foregoing and the manner in which the various objects are attained, reside in the specific construction and aggroupment of the elements peculiar to this structure, as will become apparent from a more complete examination of this specification, in the claims of which there are assembled certain specific combinations 01' parts and specific construction indicative of the scope and spirit of the invention.

Referring to the drawings, in which like symbols designate corresponding parts throughout the several views:

Figure 1 is a longitudinal cross sectional view of a tool assembly embodying the invention.

Figure 2 is a cross sectional view taken in a plane indicated by line 2--2 in Fig. 1 and looking in the direction 'of the arrows.

Figure 3 is a cross sectional view taken in a plane indicated by line 3--3 in Fig. 1 andlooki'ng in the direction of the arrows.

Figure 4 is a cross sectional view taken ina plane indicated by line 44 in Fig; llooking in the direction of the arrows and showing the valve in opened position, while Figure 5 is a view corresponding to Fig. 4 but showing the valve in closed position.

Figure 6 is an end elevational view of the tool looking in the direction of the arrow 6 in Fig. 1.

Figure '7 is a partial longitudinal cross sectional view taken in a plane indicated by line 1-1 in.

assembly which is substantially cylindrical and preferably made of tubing and comprises one main portion 9 and a contiguous rear portion l0 mounted for rotation relative to each other as hereinafter explained. The main housing portion 9 has its free end threaded as at II to receive a front end I2, while the other end is internally reduced to form an internal annular shoulder HI. Closely fitted within the housing main portion 9, there is a stator [5 held against movement relative thereto by any suitable means such as a dowel I6.

clamped between the rear or right end of the stator I 5 as seen in Fig. 1 and the annular should'er I4 of the housing main portion l0, there i's a valve block 1'! constituting an end wall for the main portion 9 and a bearing plate 18, both Secured against movement relative to the stator by a dowel I9. Also clamped between the other end of the stator and the front end I2, there is a bearing plate 20, provided with a sleevelike portion 2| which extends forwardly from the plate proper into an enlarged counterbore 36' formed within the front end 12. The counterbore 36 is deeper and larger than thelength and di am'eter respectively of the sleevelike portion 21..

to provide therebetween a cup shaped chamber 31. Extending from the bottom of the counterbore 36 centrally through the front end I 2, there is a bore 66. Also'leading from the bottom or the V plate 29.

counterbore to the exterior of the front end I2, there are two or more ports 61 which are in parallel with the bore 66.

The stator I is provided with the usual cylindrical rotor chamber 22 which extends therethrough in eccentric relation with the central axis of the stator. In the chamber 22 is rotatably mounted a rotor 23 having a shafted end 24 which extends through the bearing plate I8 and is journalled within a ball bearing 25 accurately mounted within the valve block II.

The rotor 23 also extends through the bearing plate 29 where, on the front end thereof, it is machined to form a shaft portion 26 journalled within a ball bearing 2'! accurately mounted within the sleevelike portion 2| of the bearing After the shaft portion 26, the rotor 23 extends through the front end I2 and is threaded to form a spindle 28 on which can be screwed a tool receiving member such as a collet chuck 29, which chuck is of a diameter smaller than that of the bore 66, to provide therebetween an annular clearance 68.

As'is common in tools of this type, the rotor 23 is cylindrical and journalled within the bearings 25 and 21 in coaxial alignment with the longitudinal axis of the stator and of a uniform diameter between the two bearing plates I8 and 29 calculated to produce a line contact between rotor and stator at a place indicated by 39 in Fig. 3.

Adjacent the bearing plate 29, the normal diameter of the rotor is reduced to form a collar 3| which extends through the plate. The rotor isalso provided with radially extending equally spaced slots 32, which heretofore were extending only between the equivalent of the bearing plates I8 and 29. In my improved construction, the slots 32 are extending longitudinally from the inner side of the plate I8 to the outer side of the plate 29. In other words, these slots are extended into the collar 3| for the purpose which will be hereinafter described. In the slots 32, are radially movable vanes 33 extending only between the bearing plates I9 and 29.

Intermedate the end of the bore in the bearing plate 29 through which extends the rotor collar 3|, there is provided an annular groove 34 which is in constant communication with the bottom of the rotor slots 32. From the groove 34, ports 35 lead radially in the plate 29 and then longitudinallyinto the cup shaped chamber 31.

The valve block I! which is clamped within the housing 19, has a central cylindrical stem extending'rearwardly therefrom and machined adjacent the valve block to form a cylindrical valve seat 38 and a threaded shank 39. Rotatably mounted on the valve seat 38 in fluid tight engagement therewith, there is a ring valve 49 having its inner side wall 4| also in fluid tight engagement with the outer side wall of the block II, which wall forms an annular valve seat 42. The external wall of the ring 49 is closely fitted within the housing rear portion I9 and rigidly secured thereto by a side screw 43. Toward its outer or free end, the portion I9 is slightly tapered and terminated by an inturned end wall 44 provided with a central bore 45 through which extends inwardly a motive fluid connection member 46. This member is provided with a threaded flat bottom bore 41 through which it is screwed on the threaded shank 39 with the bottom of the bore 41 forcibly engaging the end of the shank in fluid tightengagement therewith. The inner end ofn the member 46 extends close to the cute side wall of the ring valve 49 but does not engage the latter. Intermediate its ends and. within the rear portion I9, the member 46 has securely mounted on it a split spring ring 48 on which rests one end of a compression spring 49 while the other end rests against the outer wall of the ring valve 49 for maintaining its inner side 4| in fluid tight engagement with the valve seat 42 of the block IT.

The motive fluid connection member 46 protrudes beyond the casing I9, where it is shaped to receive a wrench-for screwing it tightly on the shank 39. That protruding end of the member 46 is also provided with a threaded bore or connection 59 adapted to receive the discharging end of a motive fluid conveying conduit. In the bore 59, but below the threads thereof, is mounted a disk like screen 5| held in position by a pressed in ring 52. From the screen 5| the bore 59 extends into the bore 4'! through a reduced hole or port 53, which is in communication or registry with a similar port 54 provided within the stem of the valve block II. From the port 54, communication is provided with the cylindrical valve 38 through a port 55.

In the valve block I1 and bearing plate I8 is provided a port 56 located in the same vertical plane as the port 55, and capable of communication therewith through a right angle port 51 provided in the ring Valve 40. The other or inner end of the port 56 opens into a chamber 58 formed in the stator I5 and extending substantially the full length thereof at'a place adjacent to the line contact 39. Leading fromthe chamber 58 into the rotor chamber 22, there is a plurality of inlet ports 59 which open in that chamber Within from the line contact 39.

On the other side of the line contact 39, the

stator is provided with an exhaust chamber 69 which extends substantially the full length thereof, and communicates with the rotor chamber 22 through exhaust orifices 6 I. The exhaust chamber 69 opens into the housing rear portion I9 through a passageway 62 which extends through the bearing plate I8, valve block I1, and ring valve 49 as clearly shown in Fig. '7. In the end vertical wall of the portion I9, there is provided a plurality of exhaust ports 63.

Pressed into the valve block I! and protruding therefrom through the outer side wall thereof,

. there is a stop pin 64 which has its protruding end fitted within an arcuated groove 65 provided in the inner side Wall of the ring valve 49 for limiting rotation of the valve relative to the valve block II.

In the operation of the tool, the operator will normally hold the tool to the work by grasping it with one hand around the housing main portion 9 toward the front end I2, and the other hand on the portion I9. Since the ring valve 49 is rigidly secured to the rear portion I9 by the screw 43, it can be actuated by a simple twist of the operators hand holding on the housing rear portion I9. It is therefore clear that while constituting a handle for holding the tool to the work, the rear portion I9 also forms the throttle valve handle.

With the ring throttle valve in open position as shown in Fig. 4, which position is assured by the stop pin 64 engaging one end of the arcuated slot 65, the motive fluid admitted into the bore 59 of the connection member 46, will flow to the cylindrical valve seat 38 through the ports 53,;

54 and 55. In this open position of the valve, its angular port,;5|, is located to afford complete communicationrbetween the ports 55 and 56,

thereby enabling motive fluid to beadmittediinto theinletl chamber 58 andinto the rotor chambers 22 through the inlet portsc59. Once in the rotor Seals to "prevent" leakage of i the pressure l fluidi from the port 55 to the-port 56,- The first*seal,-

chamber 22, the motivefluid will act on thevanes 33in manner common to: toolsofthis type for imparting rotation to the rotor 23 and therefrom to the spindle 23-and tool receiving chuck-29z It is also'the common practice inltools of this type to fit the vanes 33'closely within theslots 32 to prevent seepagelof the motive: fluid under the vanes, which if allowed to remain there would cause the vanes to bear excessively against the.

inner wall of the rotor chamber and cause the consequential wear of the vanes as. well as-' reduceuthe: efficiency of the tool. However; since the vane 33. must be free to move radially within the. slots. 32, it is diflicult and expensiveutoprovidexa perfectfit between the vanes andthe side: walls of the slots. Furthermore the rapid in and bearing plate 20, and the annular groove 34 has been provided to afford constant communication with the bottom of the slots, thereby enabling pressure fluid which'may have seeped under the vanes, to exhaust therefrom via the slots 32,

groove M and ports 35, which ports open into the cupshapedchamber 31: From the chamber 3?, the. exhausting fluid will flowto the exterior of the front end I2 through the ports 51 and annular clearance 68.

In a tool of this type, the chuck 29 is often used to receive a small grinding or sanding wheel, which, in performing work, creates a considerable amount of dust with detrimental effects to both the operator and the motor. This difficulty is overcome by the exhausting fluid from the chamber 31 flowing through the ports 6'! for blowing the dust away from the operator and tool and through the clearance 68 for positively preventing admission of dust into the motor.

After the driving action of the motive fluid on the vanes 33 for imparting rotation to the rotor, the motive fluid is free to exhaust from the rotor chamber 22 through the exhaust ports 6|, exhaust chamber 60 and passageway 62 into the housing end portion In, which has a volumetric capacity much greater than that of the passageway 62. From there, after further expansion, it is free to exhaust through the exhaust ports 63, which have a combined area large enough to enable exhaust of the motive fluid from the housing end portion I!) under much reduced pressure. It is therefore evident that in addition to its use as a hand grip lfOI the tool and an operating handle for the throttle valve, the rear portion I0 is further used as a decompression chamber for the exhausting motive fluid, thereby enabling the exhausting fluid to finally reach the outside of the tool under very low pressure, and consequently without any noise or danger to the operator.

When the throttle valve 40 is positioned as shown in Fig. 5, which position is assured by the stop pin M engaging the other end of the arouated slot 65, the angular valve port 51 is out of jjfcommunication with the ports 55 and 56, thereby preventing admission of the motive fluid to the 3 motor.

In this off or closed position, the throttle valve is actually provided with two efficient which maybe referred to as aisemicylindrical seal, is obtained by the close:fit of= the valveeon the cylindrical valve seat 38, o -morevparticu-- larly because'of closed engagement of these two parts between the adjacent'edges ofthe ports=55 and 51; The other seal, which may be. referred to as aiflat seal, is obtainedby: the forceful emf is gagement of the inner sidewall of the valve lfl 1,

against the outer side wall ofthe valve: block l1; which engagement-"is effected by the spring 49; More particularly, this flat seal is the engage ment ofthevalve with the'valve blocl: between the adjac'ent'edgesof the ports 55 and 511.

The screen 51' has been provided-to preventadmission of foreign matter into the tool-1 Under certain conditions of operation, it may be necessary to provide throttle valvezwhich will automatically return to the closed position" whenreleased by the-operalor. In such eventi, the compression spring 49 could -be-changedto a compression-torsion spring with-one endfastened to the member as. and the other end to the valve rm. Equipped'with this typeofspring the valvecould be maintained opened by- -the operator against the-torsion spring and be-re leased for automatic movementintoclosed p0- sition by the action of the spring.

What is claimed is: l 1. In a tool of the character described; a cylin drical housing comprising amain and a rear portion capable of relative rotation; a-fluid actuat ed motor wi.hin said main portion, an'end wall? for said main portion having astem extending;-

therefrom into said rear portion, avalve seatbn said end wall and a valve seat on said sterni'a motive fluid connection on said stem, motive fluid conveying ports leading from said end Wall seat to said motor and from said stem seat to said connection, a rotatable valve in fluid tight engagement with said seats, means in said valve responsive to its rotation affording or preventing communication of the ports leading from said seats, and a driving connection between said valve and rear portion whereby rotation of the latter is transmitted to the former.

2. In a tool of the character described, a cylindrical housing comprising a main and a rear portion capable of relative rotation, a fluid actuated motor within said main portion, an end wall for said main portion having a stem extending therefrom into said rear portion, a valve seat in said end wall and a valve seat on said stem, a motive fluid connection on said stem, motive fluid conveying porls leading from said end wall seat to said motor and from said stem seat to said connection, a rotatable valve in fluid tight engagement with said seats, spring means within said rear portion active on said valve for assuring it fluid tight engagement with one of said seats, means in said valve responsive to its rotation afiording or preventing communication of the ports leading from said seats, means between said end wall and valve for limiting the extent of rotation of the valve, and a driving connection between said valve and rear portion whereby r0- tation of the latter is transmitted to the former.

3. In a tool of the character described, a cylindrical housing comprising a main and a rear portion capable of relative rotation, a fluid actuated motor within said main portion, motive fluid conveying ports in said housing leading to said motom a throttle valve for controlling said poixs and -connected to said rear portion for-rotation therewith, an expansion chamber. within said rear portion, exhaust ports. leading from said motor'to said expansion chamber, and passage vvays leading from said chamber'to the exterior of-said rear portion.

14 In a tool of the character described, a tubu lari cylindrical housing comprising a main porti'on having a spindle projecting through the free en 'd thereof, a rear portion for said housing contiguously disposed relative to said main portion and having a motive fluid connectionextendin-g through -its free end, a motive fluid actuated motor within-said main portion operatively associated 'witli 'said spindle for imparting rotation theret motive fluid conveying ports leading from saidconnection to said motor, a rotary valve between said connection and motor for controlling said ports, means including said rear portion for manuall rotating said valve, andmeans enaf 'blilflgfgxhaust of the motive fluid from said motor .to he-gexterior of said. housing-via the interior *2 of said rear portion. ln a tool of the character-- described, acylin- I dr a1 housing comprising a main andre'ar-por- I ltion capable of relative rotation, a'fluid yactu ,atied motor within said 'm ain portion', a stem ex' tending axially from said main portion through said rear portion, a-motive fluid connection onsaid stem. motive fluid conveying ports leading' from said connection-"t0 said motor, a rotatable the aforesaid'rear rtion of said housing, and

-'fspring means car edhy said stem yieldingly aintain g said, alve and rear portion ina 1ong 30-" valveimsaid housing for controlling said ports;

aiihandldyigidly secured to said valve forming Imam 6. In a tool oi the character described, a cylin 'dric'al housing comprising a main and rear portion capablefof relative rotation a fluid actuated motor within'said main portion, an expansion chamber Within said rear portion, a stem extending axially from said main portion through said chamber, a motive fluid connection on said 'stem, motive fluid conveying ports leading from said connection to said motor, a rotatable valve insaid housing for controlling said ports, a handle rigidlysecured to said valve forming the aforesaid rearportion of said housing, a compression springzcarried bysaid stem yieldingly maintaining-said; valve and rear'r'portion in a longitudinally'fixed position relative to said main portion, exhaust ports leading from said motor. to said. expansion chamber, and passageways leading from said chamber to the" exterior of said rear portion. 7 r

PAUL E. SCHMID.

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